Railway-traffic-controlling apparatus



Patented July 13, 332%.

ROBERT M. GILSON', OF PITTSBURGH, PENNSYLVANIA, ASSIGNOB TO THE 'UNZON' SWITCH 8t SIGNAL COMPANY, OF Si/VISSVALE, PENNSYLVANIA, A CORPORATEON GE PENNSYLVANIA.

RATLVJAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed June 11, 1924. Serial No. 719,333.

- claims. 1

In the accompanying drawing, Fig. 1 is a diagrammatic view showing one form of trackway apparatus embodying my invention applied to a stretch of track over which trallic moves in only one direction. Figs. 2 and 3 are views showing two modifications of the apparatus illustrated in Fig. 1 and also embodying my invention. Fig. 4t is a view showing still another form of apparatus embodying my invention as applied to a single track road over, which traitlc moves in both directions. Fig. 5 is a View showing a modified form of apparatus shown in Fig. 2 applied to alternating current track circuits and embodying my invention.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 1, the reference characters 1 and 1 designate the track rails of a railway over which traffic normally moves in the direction indicated by the arrow. These rails are divided by means of insulated joints 2, into a plurality of track sections, only one such section, AD, being shown in the drawing.

Section AD is supplied with track circuit current from some suitable source of energy such as a track battery 8 connected across the entrance end of the. section. Two rack relays R and R? are connected across the rails at the entrance end and exit end of the section respectively, and are responsive to current supplied by battery 8. Either or both of these track relays may be used to control traffic governing apparatus in any desired manner. As shown in the drawing a signal 5 located at point A is provided with an operating circuit including a front contact 51 of relay R The signal F therefore indicates proceed when relay R is energized and stop when this relay is de-energized.

The section to the right of point D is provided as usual with a line relay H arranged to be energized only when traflic conditions in advance of section A-D are safe. As here shown this relay is controlled by contact of track relay R but it may in some instances be also controlled by other instrument-alities.

Means are also provided for at times supplying the trackway with alternating train cont-rolling current. It should be here pointed out that the trackway apparatus herein shown and described is suitable for, though in no way limited to, cooperation with train. carried governing means arranged to give a less restrictive indication on board the train when the stretch of track occupied by the train is supplied with train controlling current, but 'to give a more restrictive indication when such current is in terrupted. In at least one form of train carried apparatus arranged to cooperate in this manner the governing apparatus is controlled by the trackway train controlling current through the medium of receiving apparatus located in advance of the forward axle on the train. Since the train controlling current flows in the track rails it is imperative that the source of such current be connected with the rails in advance or" the train because otherwise the train controlling current would be shunted away from the receiving apparatus by the wheels and axles of the train.

I, therefore, provide a transformer T having its secondary 3 connected across the rails adjacent the exit end of the section. An impedance is interposed between secondary 3 and one rail 1 of the section in the usual manner. The circuit for primary 4: of transformer '1" may be traced from one terminal B of a suitable source of alternating train controlling current not shown in the drawing through frontcontact 6 of relay H, wire 24, primary l of transformer T, wire 25,

back contact 7 of relay R, and back to terminal Y of the same source. It is thus plain that alternating train controlling current is supplied to section AD only when relay R is tie-energized and relay H is energized.

The operation of the apparatus is as follows:

. As shown in the drawing all the parts are ill) let)

in the position corresponding to an unoccupied condition of the track. Under these conditions, current supplied to section AD by battery 8 causes both track relays to be energized. Signal F therefore indicates proceed. Relay H is also energized. The circuit for transforn'ier T is, however, broken at back contact 7 of relay R and no train controlling current is supplied, under these conditions, to section A-D.

I will now assume that a train moving in the direction of the arrow, approaches sec tion AD. As this train enters section AD, relays R and R both become de-enet'gized, signal F then indicates stop, and the circuit for transformer T is then completed at back contact 7 of relay R. Train controlling currentis then supplied to section AD by transformer T and the train receives the less restrictive indication as it proceeds through the block.

If relay H were deenergized, as by the presence of a train in the section to the rightof point D, and a train should enter section AD, the de-energization of relay R would not complete the circuit for transformer T, and the second train, being deprived of train controlling current, would receive the more restrictive indication.

ITndc-r certain conditions of operation, such as with a long track section and a short train, relay R might become energized after a. train had passed point A and before the train had moved completely out of the section. If this should happen the circuit for transformer T would be opened and the train would receive a more restrictive indication even if traffic conditions in advance were safe.

This is undesirable, and to prevent its occurrence I may arrange the apparatus as shown in Fig. 2. In this modification section A-D is provided, as before, with a track battery 8 and two track relays R and R Line relay H is controlled as before, and in addition I provide an auxiliary or stick relay S. When relay H is energized and relay R becomes de-energized, a pickup circuit is closed for relay S over which current flows from terminal B, through front contact 9 of relay H, wire 10, winding of relay S. wires 11 and 12, and back contact 7 of relay R to terminal C. It will be plain that this circuit is closed as a train enters sect-ion AD. Relay S is subsequently maintained in its energized condition by current through a stick circuit which passes from terminal B, through front contact 9 of relay H, wire 10, winding of relay S, wire 11, front contact 13 of relay S, wire 1%, front contact 15 of relay R for the section next in advance, to terminal C. This circuit will be closed as long as relays R and H are energized and will prevent the deenergization of relay S even if relay R should become energized before the train leaves section AD. lVhen relays S and H are both energized current is supplied to transformer T from terminal X through front contact 6 of relay H, wire 17, front contact 18 of relay S, wire 1?), primary & of transformer T, and back to terminal Y.

t should be noticed that with the apparatus illustrated in Fig. 2, after the train enters section AD, the relay S held in its energized condition over a front contact on relay R and that train controlling current will therefore be supplied to section AD till the train enters the section in advance even though relay R should become energized. The de-energization of relay H will result in an interruption of train controlling current as in Fig. 1, thus protectins following trains.

Referring now to Fig. 3, the apparatus is the same as shown in Fig. 1, except that track relay R is here connected in series with battery 8, instead of across the rails as in Fig. 1. Relay R is so proportioned and designed that when section ;&D is unoccupied, relay R is tie-energized, but when a train enters section AD, the increased current through relay R causes the relay to become energized. \Vith this modification, the current for transformer T is carried over a front contact 7 of relay R instead of by back contact 7 as in Fig. 1. The operation of the apparatus is the same as in Fig. 1 and will be understood without further explanation. Obviously, the apparatus at location A of Fig. 3 may be used with the apparatus shown at location D in Fig. 2 if desired.

In the modification shown in Fig. l, the section of track AD adapted for traflic in either direction. Relay R is connected across the rails adjacent the exit end of the section as before. A track battery 8 and track relay R are connected in series across the rails adjacent the entrance end of the section and adjusted as explained in connection with Fig. -3 so that relay It will he energized only when section Al) occupied. A second line relay ll controlled so that this relay is energized only when traffic conditions to the left of point A are safe, this control, as here shown, being accomplished by contact 51 of track relay R", although other instrumentalities may enter into the control of relay H Secondary 3 of transforn'ier T is connected. as before, across the rails adjacent the right hand end of section AD and the circuit for the primary of this transformer is the same as in Fig. 3. To supply train controlling current for trains moving from right to left, I provide a second transformer T located at point A and having its secondary 19 interposed in series with battery 8 and relay R. This transformer is ener gized when relay H and relay R are both energized, the circuit pasing from terminal X, through front contact 27 of relay H wire 26, primary 20 of transformer T, wires 23 and 25, and front contact 7 of relay R, back to terminal Y. When this circuit is closed train controlling current is supplied to section AD by transformer T 7 It is undesirable however, for this current to pass through relay R, and I therefore connect an inductive impedance 21 in series with relay R and provide a non-inductive resistance 22 as a shunt around this impedance 21and relay R. The impedance 21 and the winding of relay R offer a high impedance to alternating current and a large part of the train controlling current will therefore flow through resistance 22. The ohmic resistance of the impedance 21 and relay R is, however, very much less than that of resistance 22 and hence mostof the track circuit current from battery 8 will traverse the relay R.

The operation of the apparatus for trains moving from left to right is the same as in Fig. 3, and the operation for trains in the opposite direction will be understood without further explanation. v

Referring now to Fig. 5, the battery 8 is replaced by a track transformer designated by the reference character K and the secondary d1 ofwhich is constantly connected across the rails adjacent the entrance end of section AD which is here shown adapted for traffic moving in the direction of the arrow. he primary 4O oftransformer K is constantly supplied with alternating current from some suitable source not shown in the drawing. Relays R and R are responsive to the track circuit current supplied to the rails by transformer K.

Associated with track relay R is a stick relay S provided with a pick-up circuit over which current flows from terminal B of a suitable source of energy not shown in the draving, through the winding of relay S, wires 11 and 12, and back contact 7 a of relay R back to terminal C. This circuit is closed only when relay R is de-energized under which condition relay S is energized. The stick relay S is subsequently held in its energized condition, as long as relay R de-energized, by current over a stick circuit which may be traced from terminal 13; through the winding of relay S, wires 11 and 11 front contact 13 of relay S, wire 1d, back contact of track relay R and back to terminal C. The reference character H designates a line relay for the control of apparatus in the section to the left of A, and provided with a circuit which passes from terminal B through front contact 31 of relay R wire 32, back contact of relay S,wire 84, front contact 35 of relay 3, and winding of relay H to terminal C It follows'that relay H is energized only when relay S is de-energized and relays R and Fit are both energized, that is, when section A-D is unoccupied. Relay H is controlled by trafiic conditions in the section to the right of point D in the same manner as just described for the control of relay H by traffic conditions in section rtD. Vhen relays H and S are both energized current flows from terminal X of suitable source of alternating current through front contact 6 of relay H wire 17, front contact 18 of relay S, wire 19, primary i of transformer T, and back to terminal Y of the sai is source. When this circuit is closed train controlling current is supplied to the rails of section A-D by transformer T. In the preferred embodiment of my invention the frequency of the train controlling current is different from V the frequency of the alternating track circuit current and relays R and R are re sponsive only to track circuit current. With this arrangement it is impossible for current f om transformer T to pick up the relays.

As shown in the drawing relays R, R H and H are energized and relay S is therefore d e-energized. Train controlling current is not supplied to section A-D, the circuit for transformer T being open front contact 18 of relay S. If a train proceeds into section A-D, relays R, R and H are all de-energize-d. The closing of back contact 7 of relay R completes the pick-up circuit for relay S which in turn completes, at front contact 18 thereon, the circuit for transformer T. The train will therefore receive a proceed indication. If, after the train has passed point A and before the train passes out of section A-.-D, relay R should'pick up, relay S will still be maintained in its energized condition by virtue of its stick circuit now closed over back contact 30 of relay R Should relay R tend to pick up, duefor example to the presence of stray currents in the track rails, the opening of back contact 30 will immediately de-energize relay S and interrupt the supply of train controllingcurrent to section A-D. Should relay H be de-enen gized, as by the presence of a train in the section to the right of point D, the picking up of relay S will not complete the circuit for transformer T, this circuit then being broken at front contact 6 of relay H I do not in this application claim the combination of a source. of alternating track circuit current connected with the rails at the entrance end of the section, and a source of alternating train controlling current of different frequency connected with the rails at the exit end of the section, this combination being disclosed and claimed in my copending application Serial No. 732,927,

see

filed August 19. 192-2, for railway trattic controlling apparatus.

Although signal F and the control thereof by relay R are illustrated only in Fig. 1, these features may be used in connection with the apparatus illustrated in each of the other views and are only omitted from such other views for the sake of simplicity.

In each of the terms of apparatus herein illustrated and describec. it. should be noted that should relay R stick in the energized position, signal F would indicate proceed. even though a train occupied section AD. It is. however. extremely unlikely that both relays R and R would stick in ener .ed positions at the same time and the de-energization of relay R would permit train controlling current to be supplied to the section. The train will then be pe mitted to move through the section under a proceed indication on the train. It a following train should atte i t to enter the section past the signal F stuck clear, such second train would receive a stop indication since trafiic cont-rolling current from tran inuwould then be shunted away from the 1 second train by the wheels and axles of the train already occupying the seztion. is soon as the first train left the section the second train would receive a proceed indication and would be permittet to continue through the section. One advantage of this feature is that instead of stopping a train automatically at a false proceed wayside signal, the train is permitted to proceed and I thereby reduce the possibility of collision due to a following train proceeding under the t'alse signal indication. which possibility would arise if the train governing current were controlled by relay R.

Une advantage of my invention is tout the supply of train controlling current is normally discontinued from the section and is applied only when a tain actually occupies the section.

Although I have herein shown and described only a few forms and arrangements of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within "he scope of the appended claims without departing from the spirit and scope of invention.

Having thus described my invention, what I claim is:

1. In combination, a stretch of railway track, a t 'ack relay connected with the rails adjacent one end of said stretch. a source of track circuit current connected across the rails adjacent the other end of the stretch. a second track relay connected with the rails of said stretch adjacent said source. trallic governing means controlled by said first track relay, a line relay arranged to be energized only when traffic conditions in advance of said stretch are safe, and means controlled by said second track relay and by said line relay for at times supplying train controlling current to the rails of said stretch.

In combination, a stretch of railway track, a track relay connected with the rails adjacent one end of said stretch, a source of track circuit current connected across the rails adjacent the other end of the stretch. a second track relay connected with the rails of said stretch adjacent said source. trallic governing means controlled by said first track relay, a line relay arranged to be energized only when tratlic conditions in advance ol said stretch are safe. and means controlled by said second track relay and by said line relay for at times supplying train controlling current to the rails of said stretch acjacent the first mentioned track relay.

3. In combination. a stretch of railway track. a track relay connected with the rails adjacent one end of said stretch. a signal controlled by said relay. a source of track circuit current connected across the rails adjacent the other end (it the stretch. a second track relay connected with the rails of Silltl stretch adjacent said source. a line relay arranged to he energized only when trallic conditions in advance of said stretch are sate. a trans'tormer connected with the rails of said stretch and means including a front contact on said line relay and a hack contact on said second track relay For supplying current to said transformer.

st. In combination, a stretch of railway track. a track relay for said stretch. trafl'ic governing means controlled by said relay. a second track relay for said stretch. a line relay arranged to be energized only when tralfic conditions in advance of said stretch are safe, an auxiliary relay controlled by said second track relay and said line relay, and means control ed by said auxiliary relay tor at times supplying alternating train controlling current to said stretch.

In combination. a stretch of railway track. a track relay tor said stretch. a line reh'y arranged to be energized only when tra'liic conditions in advance of said stretch are safe, a second track relay connected across the rails in advance of said stretch, a stick relay arranged to he energized. when said line relay is energized and said first track relay is de-energized and to be subscqucntly maintained in its energized condition as long as said line relay and said second track relay are both energized. and means for supplying alternating train controlling current to the rails of said stretch when said stick relay is energized.

6. In combination, a stretch of railway track, a track relay for said stretch, a line relay arranged to be energized only when traflic conditions in advance of said stretch are 7 safe, a second track relay connected across the rails in advance of said stretch, a stick relay arranged to be energized when said line relay is energized and said first track relay is de-energized and to be subsequently maintained in its energized condition as long as said line relay and said second track relay are both energized, a trans former having a secondary winding connected across the rails of said stretch; and a circuit for the primary of said transformer including a source oi train controlling current, a front contact on said stick relay, and a front contact on said linerelay.

7. In combination, a stretch o1 railway track, a track circuit for said stretch including a source of track circuit current and a track relay, a signal controlled by said track relay, a second-relay connected with the rails of said stretch, and means for supplying train controlling current to the rails of said stretch it and only if said second relay is operated due to the presence oi a train in the stretch.

8. In combination, a stretch of railway traclr, a track circuit for said stretch includ ing a source of track circuit current and a track relay, a signal controlled by said track relay, a second track relay connected with the rails of said stretch, and means for supplying train controlling current to the rails of said stretch it and only it said second track relay isde-energized.

9. In combination, a stretch of railway track, a track circuit for said stretch including source of track circuit current adjacent the entrance end and a track relay adjacent the eXit end of the stretch, a signal controlled by said track relay, a second relay connected with the rails adjacent the entrance end of said stretch, and means for supplying train controlling current to the track rails adjacent the exit end of said stretch it and only if said second relay is operated due to the presence of a train in the stretch 10. In combination, a stretch of railway track, a track circuit for said stretch including a-source of track circuit current and a track relay, a signal controlled by said track relay, a second relay connected with the rails of said stretch, and means for supplying train controlling current to the rails of said stretch it and only it said second relay is operated due to the presence of a train in the stretch, and trailic conditions in'advance oi said stretch are sa'fe.

11. In combination, a stretch of railway track, a track circuit for said stretch in eludinga source of track circuit current and a track relay, a signal controlled by said track relay, a second track relay for said stretch, an auxiliary relay, means. or energizing said auxiliary relay if and only it said second track relay is operated due to the presence of a train in the stretch, means for subsequently keeping said auxiliary relay energized until the train leaves the stretch, and means for supplying train controlling current to the rails of said stretch while said auxiliary relay is energized but not when it is tie-energized. i

12. In combination, a stretch of railway track, a track circuit for said stretch including a source of track circuit current adjacent the entrance end and a track relay adjacent the exit end of the stretch, a signal controlled by said track relay, a second track relay for said stretch, an auxiliary relay, means for energizing said auxiliary relay it and only it said second track relay is operated due to the presence of a train in the stretch, means for subsequently keepingsaid auxiliary relay energized until the train leaves the stretch, and means for supplying train controlling current to the track rails adjacent the exit end of said stretch while said auxiliary relay is energized but not when it is ole-energized.

In testimony whereof I aflix' my signature.

ROBERT M. GILSON. 

